WASHINGTON — Prior to his nomination as attorney general last year, then-Alabama Sen. Jeff Sessions met with the Russian ambassador to the United States, but did not disclose the contacts during questioning during his contentious confirmation, Justice Department officials confirmed late Wednesday.

Sessions, who took office last month as the nation's chief law enforcement officer, met with Russian ambassador Sergey Kislyak twice last year — in July and September — while the FBI investigated Russia's meddling in the U.S. election. Sessions' meetings with the ambassador were confirmed by his spokeswoman, Sarah Isgur Flores, and another Justice Department official, who is not authorized to comment publicly.

In a released statement late Wednesday, Sessions denied discussing campaign-related matters with Russian officials.

"I never met with any Russian officials to discuss issues of the campaign," Sessions said. "I have no idea what this allegation is about. It is false."

Yet when asked in January by Sen. Al Franken, D-Minn., whether he was aware if campaign associates had any contact with Russian government officials, Sessions said he did not have knowledge of such contacts nor did he communicate with Russian officials.

He provided a similar response to written questions submitted by Sen. Patrick Leahy, D-Vt.

"There was absolutely nothing misleading about his answer,'' Flores said in a written statement, adding that Sessions took those meetings as a member of the Senate Armed Service Committee and not as a surrogate for President Trump's campaign.

Sessions himself issued a terse statement last night, saying simply, "I never met with any Russian officials to discuss issues of the campaign. I have no idea what this allegation is about. It is false."

The disclosures about Sessions communications, first reported by the Washington Post, come as calls have mounted for Sessions to recuse himself from overseeing the FBI's continuing investigation into suspected contacts between Trump associates and Russian officials.

Late Wednesday, California Rep. Adam Schiff, the ranking Democrat on the House Intelligence Committee, said that it was now "essential'' that the attorney general remove himself from any involvement in the federal inquiry.

"If reports are accurate that Attorney General Sessions — a prominent surrogate for Donald Trump — met with Ambassador Kislyak during the campaign, and failed to disclose this fact during his confirmation, it is essential that he recuse himself from any role in the investigation of Trump campaign ties to the Russians,'' Schiff said.

"This is not even a close call; it is a must."

Maryland Rep. Elijah Cummings, the ranking Democrat on the House Oversight and Government Reform Committee, went even further, calling for Sessions' resignation. House Minority Leader Nancy Pelosi, D-Calif., echoed Cummings' sentiment and requested Sessions' immediate resignation.

"After lying under oath to Congress about his own communications with the Russians, the Attorney General must resign," Pelosi said in a released statement. "There must be an independent, bipartisan, outside commission to investigate the Trump political, personal and financial connections to the Russians."

Just last month, National Security Adviser Michael Flynn was forced to resign related to his contacts with Kislyak prior to Trump's inauguration. Flynn had repeatedly denied any communications coinciding with the Obama administration's announcement of sanctions against Russia for its attempts at disrupting the U.S. elections, until acting Attorney General Sally Yates informed Trump administration officials of intercepted communications involving Flynn and the ambassador that could make the national security adviser vulnerable to blackmail.

In Sessions case, Flores said the senator had "over 25 conversations (last year) with foreign ambassadors as a senior member of the Armed Services Committee, including the British, Korean, Japanese, Polish, Indian, Chinese, Canadian, Australian, German and Russian ambassadors. He was asked during the hearing about communications between Russia and the Trump campaign — not about meetings he took as a senator and a member of the Armed Services Committee.''

The meetings involved discussions between the two countries and any prominent issues they may have been facing.

The September meeting with Kislyak was memorialized on the former senator's calendar. In July, Sessions encountered the Russian official during a Heritage Foundation event timed to the Republican National Convention.

After speaking to a group of about 50 ambassadors, a Justice official said the Russian official was among a smaller group of ambassadors who approached the senator as he was leaving the stage. The official said Sessions spoke to the smaller group whose members invited the senator to attend events they were sponsoring.

The official said Sessions made no commitments at that time.

As recently as this week, Sessions gave no indication that he intended to recuse himself, telling reporters Monday that he would only step aside if a matter emerged requiring his recusal.